Am I supposed to use a metal washer inside the tank or not?

Hello,
I'm getting ready to replace the washers and bolts connecting my American Standard Cadet 3 tank to the bowl. I just bought a tank bolt kit at Home Depot, and the guy there said to use the metal washers on both the inside and outside of the tank. In other words, he said that the metal washers were supposed to go between the bolt head and the rubber/cloth washer inside the tank and between the nut and the rubber/cloth washer underneath the tank.

However, in reading another post on this forum, someone (I've since lost the reference) said that the metal washer should not go between the bolt head and the rubber/cloth washer.

And there is a second part of my question. Where does the bottom rubber/cloth washer actually go? Does it go underneath the tank between the tank and the bowl, or does it go under the bowl?

If you have a set where for each bolt there is one rubber washer, one metal washer and a nut, then the order is bolt head in tank, rubber washer under bolt head in tank, then the metal washer and nut go under the bowl.

If you have a set where for each bolt there are two rubber washers, two metal washers and two nuts, then the order is: Bolt head and rubber washer in tank, metal washer and nut on outside of tank, then, under the bowl, rubber washer, metal washer, nut. See Korky diagram 6A HERE, for example. Or Fluidmaster instructions: HERE

Toto gives you two metal washers and only one rubber washer; they don't have you put a rubber washer under the bowl. See illustration 4 on page 5 HEREfor how to do the inside of the tank, and the text of the second paragraph of instruction 5 as to how to do the under-the-bowl.

As to your second question, the rubber washer (assuming you have two per bolt) goes under the bowl. See diagram 6A above.

Lots of handymen (and, apparently, aprons) think that you put that metal washer under the bolt head. Do that, and you are reducing the seal between the bolt head and the rubber washer, with which the bolt head should be making a watertight seal, and reducing the ability of the bolt head to seat the rubber washer against the tank. Hence, you are increasing the chance of a leak.

Bottom line, you have metal against metal underwater in a place you are trying to have a watertight seal. On the face of it, that's obviously wrong.

There is no rational reason to put the metal washer inside the bowl. I think the myth arose because dummies bought bolt sets without knowing how to do the installation, and just guessed at where stuff was supposed to go; then they showed others how to do it the same, wrong, way, and that's how many people have learned to do it. But it's irrational and totally-wrong.

Now, under the bowl, it's a different story. There, you have a nut, and you are using the nut to compress the metal washer against the rubber washer against the bowl.

By the way, the consensus on the forum is that a good-quality set that has two nuts, two metal washers, and two rubber washers per bolt gives an installation that is the least likely to leak. The idea is to make the seal between the bolt head and tank first, using the nut and metal washer. Now you have a bolt coming nice and straight out of the tank, held in place, and a nice seal between the bolt head and tank, before you even start reattaching the tank. That straight bolt, held in place, is going to make it easier to properly-reattach the tank. Put another way, the attachment hardware has two missions: (1) make a waterproof seal and (2) hold the tank in place. The way we prefer to do it, you have a set of washers and nuts for each mission and you do each mission separately: i.e. make the seal and then reattach the tank. It's possible to use one metal washer and one nut to apply the tension necessary both to make the seal and also to secure the tank on the bowl, but your long-term success rate is likely to be enhanced by doing each job separately.

Of course you still have to tighten down the tank slowly and carefully, keeping it vertical and alternating side-to-side (i.e. tighten a little on the one side, then a little on the other, so it stays basically straight as you are pulling it down to meet the bowl). Stop the moment you have any china contact against china, because one more turn and you will likely crack it. When you stop tightening, examine whether the points of contact are correct. If not, loosen, straighten and try tightening again. You should have no wobble of movement in the tank, but only a whiff of contact between china pieces.

If you want a good giggle, here's a thread on this from Dimwit City: BAD ADVICE Another good reason to hire a plumber not a handyman. (Or do it yourself with the excellent, professional advice that real plumbers Terry, HJ, Jimbo and others give here.)

WJCandee,
Thanks for your reply. I understand what you're saying, and now I completely agree with you about not using a metal washer inside the tank. But I still have a question. I don't understand the function of the rubber washer under the bowl. If, for some reason, water should penetrate the rubber washer inside the tank, that water would be able to drop to the floor since there is a space between the bottom of the tank and the top of the bowl. The rubber washer under the bowl wouldn't be able to stop that water, because the water could just run sideways to the edge of the top of the bowl and drop to the floor.
In any case, why not use a third rubber washer directly under the bottom of the tank with another nut holding it tight to the underside of the tank. Then, you'd have a rubber washer on both sides of the tank and still have a third rubber washer underneath the bowl.

As a matter of fact, I just went back to Home Depot and bought another tank and bolt kit, and the instructions on the outside of the package shows a rubber washer under the bottom of the tank. Like your advice, it has no metal washer inside the tank, but it does have a rubber washer on either side of the tank bottom.

Thanks Terry,
Well, it really wasn't a case of what they gave me. I bought a kit that had four rubber washers, four metal washers and four nuts. Then I bought a second kit, so that I'd have enough to put a set under the tank.
The only other question that I have is this: Should I use a metal washer under the tank (between the rubber washer under the tank and the nut)?
Thanks,
Louis

Should I use a metal washer under the tank (between the rubber washer under the tank and the nut)?

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You need the bolt head and rubber washer in the tank; you need a metal washer and a nut under (outside) the tank.

If you are going to put a rubber washer on the outside of the tank, it better have a metal washer between the nut and it. But I wouldn't use the rubber washer, because as it degrades over time, it potentially will cause the seal between the bolt head and washer on the other side of the tank to become less tight.

You need the bolt head and rubber washer in the tank; you need a metal washer and a nut under (outside) the tank.

If you are going to put a rubber washer on the outside of the tank, it better have a metal washer between the nut and it. But I wouldn't use the rubber washer, because as it degrades over time, it potentially will cause the seal between the bolt head and washer on the other side of the tank to become less tight.

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WJCandee,
I don't understand why you are saying that if the rubber washer under the tank degrades, that it could affect the rubber washer inside the tank. The two rubber washers don't touch each other. They would be on either side of a thickness of porcelain. How could one rubber washer affect the other one? If they were touching each other, then I might agree with you, but they won't be touching.
Louis

quote; I bought a kit that had four rubber washers, four metal washers and four nuts. Then I bought a second kit, so that I'd have enough to put a set under the tank

According to my calculations, if you use one nut on each bolt under the tank and one nut on each bolt under the bowl, you only need FOUR nuts, so why buy the second set? That "bad advice" site is the "blind leading the blind" because almost NONE of the answers were completely correct. The rubber gasket under the tank is a "user preference" it has little benefit and no detriment. If you have them, use them, but do not lose any sleep over it if they did not furnish them. Rubber washers between the metal one and the bottom of the bowl is a better choice, however.

quote; I bought a kit that had four rubber washers, four metal washers and four nuts. Then I bought a second kit, so that I'd have enough to put a set under the tank

According to my calculations, if you use one nut on each bolt under the tank and one nut on each bolt under the bowl, you only need FOUR nuts, so why buy the second set? That "bad advice" site is the "blind leading the blind" because almost NONE of the answers were completely correct. The rubber gasket under the tank is a "user preference" it has little benefit and no detriment. If you have them, use them, but do not lose any sleep over it if they did not furnish them. Rubber washers between the metal one and the bottom of the bowl is a better choice, however.

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hj, thanks for your reply. When I said that I bought a second kit, I didn't mean that I bought a second kit with bolts and metal washers. I simply bought a second kit which contained only 4 rubber washers and nothing else. I didn't elaborate on the second kit, because I was simply trying to say that I bought more rubber washers. I am sorry if my statement about the second kit was misleading.

I now want to apologize to all of you, especially WJCandee. I now see why I wouldn't want a rubber washer directly under the tank. Even though the two rubber washers wouldn't be touching each other, I now see that if the rubber washer under the tank were to wear out, the metal washer and nut below it would no long be exerting an upward force, and the washer inside the tank would no longer be held tight against the porcelain.

Again, I'm a novice when it comes to most plumbing jobs, and that's why I knew that I would get the correct answers on this forum.

Please forgive my many questions and my continued hard-headiness in not understanding what you all were telllng me.

I didn't say that I was going to put an ordinary nut against the rubber washer. My question was whether I should have a metal washer against the rubber washer underneath the tank.

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I should have been more clear. You need a washer which has a larger surface close to or equal to "any" rubber washer to distribute the force of the nut. A nut used alone might twist/deform/cut the rubber washer and a metal washer is a buffer between the two.

I know this isn't a professional recommendation. But I have run into too many defective tanks and bowls that just want to drip at the bolt holes or the fill hole washer. When this happens, it tends to be incorrect curvatures. Maybe one of the bolt holes are too close to the bottom corner of the tank where it curves upward preventing a good flat seal for the rubber washer, or the fill hole in the bowl is not round or flat enough for a new rigid rubber seal to do it's thing. and maybe over time these washers and seals will seat but getting a drip shortly after assembly is just embarassing. I don't want to risk overtightening the bolts to compensate for sloppy ceramic work by the manufacturer. So I have gotten in the habit of cheating and using clear silicone on the bolt washers and fill hole seal when assembling a tank to a bowl. It elminates the drip problem on new assemblies and my hope is that over time, the rubber seals will seat better on their own eventually. Any insights on this?